<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Service_WindowsAzure
 * @subpackage Storage
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Storage.php 23772 2011-02-28 21:35:29Z ralph $
 */

/**
 * @see Zend_Service_WindowsAzure_Credentials_CredentialsAbstract
 */
require_once 'Zend/Service/WindowsAzure/Credentials/CredentialsAbstract.php';

/**
 * @see Zend_Service_WindowsAzure_Credentials_SharedKey
 */
require_once 'Zend/Service/WindowsAzure/Credentials/SharedKey.php';

/**
 * @see Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract
 */
require_once 'Zend/Service/WindowsAzure/RetryPolicy/RetryPolicyAbstract.php';

/**
 * @see Zend_Service_WindowsAzure_Exception
 */
require_once 'Zend/Service/WindowsAzure/Exception.php';

/**
 * @see Zend_Http_Client
 */
require_once 'Zend/Http/Client.php';

/**
 * @see Zend_Http_Response
 */
require_once 'Zend/Http/Response.php';

/**
 * @category   Zend
 * @package    Zend_Service_WindowsAzure
 * @subpackage Storage
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Service_WindowsAzure_Storage
{
    /**
     * Development storage URLS
     */
    const URL_DEV_BLOB      = "127.0.0.1:10000";
    const URL_DEV_QUEUE     = "127.0.0.1:10001";
    const URL_DEV_TABLE     = "127.0.0.1:10002";
    
    /**
     * Live storage URLS
     */
    const URL_CLOUD_BLOB    = "blob.core.windows.net";
    const URL_CLOUD_QUEUE   = "queue.core.windows.net";
    const URL_CLOUD_TABLE   = "table.core.windows.net";
    
    /**
     * Resource types
     */
    const RESOURCE_UNKNOWN     = "unknown";
    const RESOURCE_CONTAINER   = "c";
    const RESOURCE_BLOB        = "b";
    const RESOURCE_TABLE       = "t";
    const RESOURCE_ENTITY      = "e";
    const RESOURCE_QUEUE       = "q";
    
    /**
     * HTTP header prefixes
     */
    const PREFIX_PROPERTIES      = "x-ms-prop-";
    const PREFIX_METADATA        = "x-ms-meta-";
    const PREFIX_STORAGE_HEADER  = "x-ms-";
    
    /**
     * Current API version
     *
     * @var string
     */
    protected $_apiVersion = '2009-09-19';
    
    /**
     * Storage host name
     *
     * @var string
     */
    protected $_host = '';
    
    /**
     * Account name for Windows Azure
     *
     * @var string
     */
    protected $_accountName = '';
    
    /**
     * Account key for Windows Azure
     *
     * @var string
     */
    protected $_accountKey = '';
    
    /**
     * Use path-style URI's
     *
     * @var boolean
     */
    protected $_usePathStyleUri = false;
    
    /**
     * Zend_Service_WindowsAzure_Credentials_CredentialsAbstract instance
     *
     * @var Zend_Service_WindowsAzure_Credentials_CredentialsAbstract
     */
    protected $_credentials = null;
    
    /**
     * Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract instance
     *
     * @var Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract
     */
    protected $_retryPolicy = null;
    
    /**
     * Zend_Http_Client channel used for communication with REST services
     *
     * @var Zend_Http_Client
     */
    protected $_httpClientChannel = null;
    
    /**
     * Use proxy?
     *
     * @var boolean
     */
    protected $_useProxy = false;
    
    /**
     * Proxy url
     *
     * @var string
     */
    protected $_proxyUrl = '';
    
    /**
     * Proxy port
     *
     * @var int
     */
    protected $_proxyPort = 80;
    
    /**
     * Proxy credentials
     *
     * @var string
     */
    protected $_proxyCredentials = '';
    
    /**
     * Creates a new Zend_Service_WindowsAzure_Storage instance
     *
     * @param string $host Storage host name
     * @param string $accountName Account name for Windows Azure
     * @param string $accountKey Account key for Windows Azure
     * @param boolean $usePathStyleUri Use path-style URI's
     * @param Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract $retryPolicy Retry policy to use when making requests
     */
    public function __construct(
        $host = self::URL_DEV_BLOB,
        $accountName = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::DEVSTORE_ACCOUNT,
        $accountKey = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::DEVSTORE_KEY,
        $usePathStyleUri = false,
        Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract $retryPolicy = null
    ) {
        $this->_host = $host;
        $this->_accountName = $accountName;
        $this->_accountKey = $accountKey;
        $this->_usePathStyleUri = $usePathStyleUri;
        
        // Using local storage?
        if (!$this->_usePathStyleUri
            && ($this->_host == self::URL_DEV_BLOB
                || $this->_host == self::URL_DEV_QUEUE
                || $this->_host == self::URL_DEV_TABLE)
        ) {
            // Local storage
            $this->_usePathStyleUri = true;
        }
        
        if ($this->_credentials === null) {
            $this->_credentials = new Zend_Service_WindowsAzure_Credentials_SharedKey(
                $this->_accountName, $this->_accountKey, $this->_usePathStyleUri);
        }
        
        $this->_retryPolicy = $retryPolicy;
        if ($this->_retryPolicy === null) {
            $this->_retryPolicy = Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract::noRetry();
        }
        
        // Setup default Zend_Http_Client channel
        $options = array(
            'adapter' => 'Zend_Http_Client_Adapter_Proxy'
        );
        if (function_exists('curl_init')) {
            // Set cURL options if cURL is used afterwards
            $options['curloptions'] = array(
                    CURLOPT_FOLLOWLOCATION => true,
                    CURLOPT_TIMEOUT => 120,
            );
        }
        $this->_httpClientChannel = new Zend_Http_Client(null, $options);
    }
    
    /**
     * Set the HTTP client channel to use
     *
     * @param Zend_Http_Client_Adapter_Interface|string $adapterInstance Adapter instance or adapter class name.
     */
    public function setHttpClientChannel($adapterInstance = 'Zend_Http_Client_Adapter_Proxy')
    {
        $this->_httpClientChannel->setAdapter($adapterInstance);
    }

    /**
     * Retrieve HTTP client channel
     *
     * @return Zend_Http_Client_Adapter_Interface
     */
    public function getHttpClientChannel()
    {
        return $this->_httpClientChannel;
    }
    
    /**
     * Set retry policy to use when making requests
     *
     * @param Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract $retryPolicy Retry policy to use when making requests
     */
    public function setRetryPolicy(Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract $retryPolicy = null)
    {
        $this->_retryPolicy = $retryPolicy;
        if ($this->_retryPolicy === null) {
            $this->_retryPolicy = Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract::noRetry();
        }
    }
    
    /**
     * Set proxy
     *
     * @param boolean $useProxy         Use proxy?
     * @param string  $proxyUrl         Proxy URL
     * @param int     $proxyPort        Proxy port
     * @param string  $proxyCredentials Proxy credentials
     */
    public function setProxy($useProxy = false, $proxyUrl = '', $proxyPort = 80, $proxyCredentials = '')
    {
        $this->_useProxy         = $useProxy;
        $this->_proxyUrl         = $proxyUrl;
        $this->_proxyPort        = $proxyPort;
        $this->_proxyCredentials = $proxyCredentials;
    
        if ($this->_useProxy) {
            $credentials = explode(':', $this->_proxyCredentials);
            
            $this->_httpClientChannel->setConfig(array(
                'proxy_host' => $this->_proxyUrl,
                'proxy_port' => $this->_proxyPort,
                'proxy_user' => $credentials[0],
                'proxy_pass' => $credentials[1],
            ));
        } else {
            $this->_httpClientChannel->setConfig(array(
                'proxy_host' => '',
                'proxy_port' => 8080,
                'proxy_user' => '',
                'proxy_pass' => '',
            ));
        }
    }
    
    /**
     * Returns the Windows Azure account name
     *
     * @return string
     */
    public function getAccountName()
    {
        return $this->_accountName;
    }
    
    /**
     * Get base URL for creating requests
     *
     * @return string
     */
    public function getBaseUrl()
    {
        if ($this->_usePathStyleUri) {
            return 'http://' . $this->_host . '/' . $this->_accountName;
        } else {
            return 'http://' . $this->_accountName . '.' . $this->_host;
        }
    }
    
    /**
     * Set Zend_Service_WindowsAzure_Credentials_CredentialsAbstract instance
     *
     * @param Zend_Service_WindowsAzure_Credentials_CredentialsAbstract $credentials Zend_Service_WindowsAzure_Credentials_CredentialsAbstract instance to use for request signing.
     */
    public function setCredentials(Zend_Service_WindowsAzure_Credentials_CredentialsAbstract $credentials)
    {
        $this->_credentials = $credentials;
        $this->_credentials->setAccountName($this->_accountName);
        $this->_credentials->setAccountkey($this->_accountKey);
        $this->_credentials->setUsePathStyleUri($this->_usePathStyleUri);
    }
    
    /**
     * Get Zend_Service_WindowsAzure_Credentials_CredentialsAbstract instance
     *
     * @return Zend_Service_WindowsAzure_Credentials_CredentialsAbstract
     */
    public function getCredentials()
    {
        return $this->_credentials;
    }
    
    /**
     * Perform request using Zend_Http_Client channel
     *
     * @param string $path Path
     * @param string $queryString Query string
     * @param string $httpVerb HTTP verb the request will use
     * @param array $headers x-ms headers to add
     * @param boolean $forTableStorage Is the request for table storage?
     * @param mixed $rawData Optional RAW HTTP data to be sent over the wire
     * @param string $resourceType Resource type
     * @param string $requiredPermission Required permission
     * @return Zend_Http_Response
     */
    protected function _performRequest(
        $path = '/',
        $queryString = '',
        $httpVerb = Zend_Http_Client::GET,
        $headers = array(),
        $forTableStorage = false,
        $rawData = null,
        $resourceType = Zend_Service_WindowsAzure_Storage::RESOURCE_UNKNOWN,
        $requiredPermission = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PERMISSION_READ
    ) {
        // Clean path
        if (strpos($path, '/') !== 0) {
            $path = '/' . $path;
        }
            
        // Clean headers
        if ($headers === null) {
            $headers = array();
        }
        
        // Ensure cUrl will also work correctly:
        //  - disable Content-Type if required
        //  - disable Expect: 100 Continue
        if (!isset($headers["Content-Type"])) {
            $headers["Content-Type"] = '';
        }
        $headers["Expect"]= '';

        // Add version header
        $headers['x-ms-version'] = $this->_apiVersion;
        
        // URL encoding
        $path           = self::urlencode($path);
        $queryString    = self::urlencode($queryString);

        // Generate URL and sign request
        $requestUrl     = $this->_credentials
                          ->signRequestUrl($this->getBaseUrl() . $path . $queryString, $resourceType, $requiredPermission);
        $requestHeaders = $this->_credentials
                          ->signRequestHeaders($httpVerb, $path, $queryString, $headers, $forTableStorage, $resourceType, $requiredPermission, $rawData);

        // Prepare request
        $this->_httpClientChannel->resetParameters(true);
        $this->_httpClientChannel->setUri($requestUrl);
        $this->_httpClientChannel->setHeaders($requestHeaders);
        $this->_httpClientChannel->setRawData($rawData);
                
        // Execute request
        $response = $this->_retryPolicy->execute(
            array($this->_httpClientChannel, 'request'),
            array($httpVerb)
        );
        
        return $response;
    }
    
    /**
     * Parse result from Zend_Http_Response
     *
     * @param Zend_Http_Response $response Response from HTTP call
     * @return object
     * @throws Zend_Service_WindowsAzure_Exception
     */
    protected function _parseResponse(Zend_Http_Response $response = null)
    {
        if ($response === null) {
            throw new Zend_Service_WindowsAzure_Exception('Response should not be null.');
        }
        
        $xml = @simplexml_load_string($response->getBody());

        if ($xml !== false) {
            // Fetch all namespaces
            $namespaces = array_merge($xml->getNamespaces(true), $xml->getDocNamespaces(true));

            // Register all namespace prefixes
            foreach ($namespaces as $prefix => $ns) {
                if ($prefix != '') {
                    $xml->registerXPathNamespace($prefix, $ns);
                }
            }
        }

        return $xml;
    }
    
    /**
     * Generate metadata headers
     *
     * @param array $metadata
     * @return HTTP headers containing metadata
     */
    protected function _generateMetadataHeaders($metadata = array())
    {
        // Validate
        if (!is_array($metadata)) {
            return array();
        }
        
        // Return headers
        $headers = array();
        foreach ($metadata as $key => $value) {
            if (strpos($value, "\r") !== false || strpos($value, "\n") !== false) {
                throw new Zend_Service_WindowsAzure_Exception('Metadata cannot contain newline characters.');
            }
            
            if (!self::isValidMetadataName($key)) {
                throw new Zend_Service_WindowsAzure_Exception('Metadata name does not adhere to metadata naming conventions. See http://msdn.microsoft.com/en-us/library/aa664670(VS.71).aspx for more information.');
            }
            
            $headers["x-ms-meta-" . strtolower($key)] = $value;
        }
        return $headers;
    }
    
    /**
     * Parse metadata headers
     *
     * @param array $headers HTTP headers containing metadata
     * @return array
     */
    protected function _parseMetadataHeaders($headers = array())
    {
        // Validate
        if (!is_array($headers)) {
            return array();
        }
        
        // Return metadata
        $metadata = array();
        foreach ($headers as $key => $value) {
            if (substr(strtolower($key), 0, 10) == "x-ms-meta-") {
                $metadata[str_replace("x-ms-meta-", '', strtolower($key))] = $value;
            }
        }
        return $metadata;
    }
    
    /**
     * Parse metadata XML
     *
     * @param SimpleXMLElement $parentElement Element containing the Metadata element.
     * @return array
     */
    protected function _parseMetadataElement($element = null)
    {
        // Metadata present?
        if ($element !== null && isset($element->Metadata) && $element->Metadata !== null) {
            return get_object_vars($element->Metadata);
        }

        return array();
    }
    
    /**
     * Generate ISO 8601 compliant date string in UTC time zone
     *
     * @param int $timestamp
     * @return string
     */
    public function isoDate($timestamp = null)
    {
        $tz = @date_default_timezone_get();
        @date_default_timezone_set('UTC');
    
        if ($timestamp === null) {
            $timestamp = time();
        }
    
        $returnValue = str_replace('+00:00', '.0000000Z', @date('c', $timestamp));
        @date_default_timezone_set($tz);
        return $returnValue;
    }
    
    /**
     * URL encode function
     *
     * @param  string $value Value to encode
     * @return string        Encoded value
     */
    public static function urlencode($value)
    {
        return str_replace(' ', '%20', $value);
    }
    
    /**
     * Is valid metadata name?
     *
     * @param string $metadataName Metadata name
     * @return boolean
     */
    public static function isValidMetadataName($metadataName = '')
    {
        if (preg_match("/^[a-zA-Z0-9_@][a-zA-Z0-9_]*$/", $metadataName) === 0) {
            return false;
        }

        if ($metadataName == '') {
            return false;
        }

        return true;
    }

    /**
     * Builds a query string from an array of elements
     *
     * @param array     Array of elements
     * @return string   Assembled query string
     */
    public static function createQueryStringFromArray($queryString)
    {
        return count($queryString) > 0 ? '?' . implode('&', $queryString) : '';
    }    
}
